When to deacidify? Before or after aging?

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Sep 25, 2022
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Carbenet Sauvignon from Santa Cruz, 12.5% alcohol, dry and lighter bodied for the type (colder year). I made a mistake and used someone else's numbers for total acid (same crush and grapes). They were off from my portion of the batch by about 1g/L. It was foolish because there are always differences and I should know better. I then added too much tartaric before my primary fermentation. This had me up at 7.6-7.8 g/L after primary ferment. Primary went off without a hitch, and then MLF was kind enough to drop me to 6.6 g/L with a final pH of 3.49. So much better, but still too much to be palatable.

The wine is young as it was crushed in Sept. So I expect it tastes green and all that. But I can tell, despite the green harsh flavors, the acid is way off balance and that is not really going to improve much. It needs to be dropped by at least another 1g/L and probably more to be balanced. I know that by aging, tartaric will drop out. But I was reading it only drops about 200-300 mg/L. That wouldn't be near enough to compensate for the harshness I am tasting.

So I need deacidify. Question is When? Before more aging and flavor/aroma development? Or do I wait until I have dropped out the last of the tartaric? I have heard that deacidification produces bubbles that wreck the delicate flavors from aging. Seems like earlier interventions are always better. What do you think?

Calcium carbonate and potassium bicarbonate both reduce acid, but can impart a metallic taste, so I use them as a last resort.

Can you chill the wine? Cold stabilization may do enough -- my cellar is 58 F in the winter and some wines drop crystals at that temperature, although for your needs, getting the wine below 40 F will produce greater results.

If it were me, I'd give the wine time: 1) any acid reduction that happens over time means less for you to address.

2) If you adjust now and acid drops later, you're in a yo-yo situation where you may need to add acid back.

If you do resort to chemical reduction, figure out how much you need and add 1/4 of that amount. Let the wine rest a month and taste. Add more if acid still needs reduction. Calcium carbonate is supposedly slow acting, so give it time. As always, it's easier to add more later than it is to take some out.

Patience is your friend in this situation.
Let time do its job, chill it if you can. I lost an entire vintage due to oxidation in a similar situation. Acid was too high so I added too much potassium bicarbonate trying to correct it, then I added tartaric acid to correct that. All that messing around introduced too much oxygen and a year later I had orange oxidized wine that I had to pour down the drain. Too much manipulation can ruin you wine. Even in a moderately cooler environment you will drop tartaric acid over time.
I would pull as much bitartrate as possible and then look at MLF. For this part of the country 28F in the garage. MLF needs heat so commercial folks wait till spring. You could warm up a carboy.
carbonate and bicarbonate would be my last resort. I would have a month minimum before bottling just in case it didn’t work as expected.
I would certainly wait, but do some things while waiting, as others have suggested let the cold stabilization do what it does, who knows maybe the amount you get will be enough to make you happy. I think now that you have fermented it, forget the numbers and make any further changes by taste, not trying to hit some magic numbers, they are seldom achievable and as reported above trying to hit them often ends up with a mess down the drain.

With this being Cabernet Sauvignon, I assumed MLF was going to be, has already been done, if not it certainly should be, if you haven't added to much SO2 already to keep it from happening. Lastly, you might want to try adding either Vegetable Glycerin and/or gum arabic both of these can add a sensation of sweetness and bench trials are certainly in order to help you decide where to go and what to do.

I am like Bryan calcium carbonate and potassium bicarbonate are both last resort things for me.
C Mason is right. Time and taste will tell you what you need. It's your wine, if it's necessary, adjust to your taste and enjoy!
Like everyone else, I say wait if you can. I think there is no fixed number for what bitartrate drops out of wine. It will depend on how much potassium is in the grapes.

Also, was your sample degassed before testing pH? CO2 will throw off your measurement.
It's your wine, if it's necessary, adjust to your taste and enjoy!
An industry point of view. A wine which is adjusted to be perfect today is at its peak in shelf life and is designed to be consumed within a year. A wine on the tannic side and a white on the acidic side are being designed for producing shelf life.

Adjust to make your product target, and enjoy.
3. 4ph doesn't sound too acidic, sometimes back sweeten a little will balance that. it's young just age it 6 months. then check. don't need to. rush it. be patient.

if it has no body perhaps a light fruity wine might be a goal instead. or add some different tannins, oak, walnut, black tea leaves, tobacco leaves,

could blend this wine later if it's not the flavor profile you wanted.

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